This is a simplified(!) version of the mechanism from yesterday's post. I'll be mounting the whole thing in a box in the morning and keeping fingers crossed that it works. I'm pleased with the way it is progressing, I'll be even more pleased if it works. The three circular pins at the lower front will fit through holes in the box side, same wth the ones at the back that you can just see. The square push rods at the top of the picture will be linked to the rower's oar, driving them in a circular motion. Hopefully a single drive, probably from the centre front pin, will drive three rowers in synchronised glory.

I had a close call here. I had spaced the holes on the two horizontal bars an arbitrary distance apart. When I put everything together the clearance between the parts was only a couple of millimeters! Phew!